Speech interpretation is a technically hard problem. After decades of development, the goal of direct voice control over electronic devices remains expensive and frustrating. The ability to activate a device by a spoken command would lead to an enormous range of valuable products. Unfortunately, most of the development effort to date has been dedicated to the interpretation of free-form natural speech, primarily for computer dictation, browsing, and general query service, although it inevitably requires powerful computers and expensive software, and often a costly wireless data link to a remote supercomputer as well. Most of the emerging voice-activation applications, on the other hand, are special-purpose devices involving just a few specific operations and just a few predetermined commands. For such applications, general speech interpretation is vastly excessive. Even with a dedicated array of supercomputers, responsiveness is far too slow and far to erratic for special-purpose devices. Prior art is particularly inadequate for those applications where an instantaneous response is needed, such as timers or triggered data acquisition systems. Furthermore, the cost of speech interpretation often dominates the manufacturing cost of small dedicated devices, which often kills the entire voice-activated product on economic grounds alone.
Examples of potential applications that are poorly served by prior-art speech interpretation are voice-activated counters, sample-and-hold voltmeters, and triggerable products derivative therefrom, as well as voice-activated distance measuring devices such as tape measures and calipers. Further examples include devices that perform a specific action other than making a measurement, such as a voice-activated solder feeder or a welding-rod advancer for when both hands are occupied, a voice-controlled industrial weighing or labeling station for efficient package handling, and voice-controlled machine shop accessories including parts counters and machine controllers. In the home, there is a need for voice-controlled faucets, preferably including both flow and temperature control to assist the disabled, a voice-activated toilet flush device also for the physically impaired, voice-activated soap dispenser and towel dispenser for improved sanitation, and a host of voice-activated kitchen gadgets, numerous voice-activated devices for athletic/sports/health activities, not to mention an infinite variety of fun and educational toys. Each of these example products does not need, and would not benefit from, a general speech interpretation capability—even if it were free.
There is also a continuing demand for new ultra-safe devices for working in a hazardous environment such as around high voltage. Workers often need to control measurement instruments or other devices in the presence of toxic chemicals, pathogens, explosives, radiation, extreme heat or cold, moving blades, presses, and many other hazards. Today, workers must activate a system or adjust a parameter using long insulating poles, an awkward and imprecise solution at best. Means are needed to do these tasks by voice commands alone, thereby enabling precise control over the action and timing of a hazardous operation, but from a safe distance.
To focus on just one potential application, there is an acute need for a signal generating device that enables users such as electronic testing engineers to control the timing of a measurement or to prompt a system under test. Everyone who uses oscilloscopes is quite familiar with the problem of triggering the scope while both hands are occupied. The user must hold two probes in place while adjusting a potentiometer or while doing something extremely critical with the circuit under test. But with both hands occupied, there is simply no way to trigger the scope when needed.
Recently an oscilloscope has become available with voice-activated features. See for example U.S. Pat. No. 7,027,991 to Alexander. This is a big step in the right direction. However the voice control is restricted to just one instrument, is not detachable, is not self-contained, and produces no output signals. A versatile device would produce a variety of output signals which would be usable on a wide range of receiving systems.
A clever command recognition method was introduced in U.S. Pat. No. 7,532,038 to Ariav, wherein electronic filters separate the command sounds into high and low frequency components. A few commands can be identified on the basis of frequency alone, but the system requires cumbersome analog electronics with dual amplification and dual or multiplexed ADC inputs. Also it ignores crucial non-sinusoidal waveform information in the sound, and is unable to differentiate among commands with silent intervals, and is unable to discriminate brief versus sustained sounds, among other limitations.
What is needed is a voice-activated device to control a measurement instrument or any electronic system, by voice command alone. Preferably such a device would be fast and extremely economical, while providing specific output signals on command. Preferably the new device would avoid completely the monumental expense and frustration of speech interpretation systems that require full-performance computers, massive software, and tedious “training”. The new device would simply produce the signal on command. Such a device would enable applications in electronic testing, industrial control, and a host of consumer items that require low-cost voice activation.